1918] Stock: The Pleistocene Fauna of Hawver Cave 473 



Kennedy fissure in the relatively large number of forms which are 

 extinct. It resembles the latter also in the presence of certain types. 

 In the Pennsylvania deposit the ground-sloths form an important 

 element of the fauna. Both Mylodon and Mcgalonyx are represented, 

 the latter by a number of species. Nothrotherium is not recorded. 

 Mijlodon occurs in the Hawver Cave accumulation apparently asso- 

 ciated with Megaton yx. Nothrotherium is, however, the principal 

 member of the ground-sloth group found at this locality. The present 

 known distribution during the Pleistocene limits the genus to Cali- 

 fornia and Texas. 



Sabre-tooth cats occur in both western and eastern fissure accumu- 

 lations, as well as representatives of Equus, a bison, and a mastodon. 

 Conspicuous differences between the two faunas rest in the absence 

 from Hawver Cave of Arctotherium, Tapirus and peccaries of the 

 genus Mylohyus, which are found in the Port Kennedy fissure. 

 Euceratherium is present in the California cave and absent from 

 the Pennsjdvania deposit. In contrast to the occurrence of the latter 

 form at Hawver Cave is the presence in the Port Kennedy deposit 

 of a ruminant, Tcleopternus orientalis. Affinity of this form to the 

 muskox, Ovibos, is suggested by Matthew. 



As a result of researches by Barnum Brown 8 on the Conrad fissure, 

 a mammal assemblage is revealed from northern Arkansas indicative 

 of a somewhat later phase of the Pleistocene than that represented 

 by the faunas from Port Kennedy fissure and Potter Creek Cave. 

 This fauna consists, according to Brown, of "thirty-seven genera and 

 fifty-one species, of which four genera and twenty-four species are 

 considered extinct. ' ' We note here a relatively much smaller number 

 of extinct genera than is characteristic of Hawver Cave. The ground- 

 sloths are totally lacking from the Conard fissure, but the sabre-tooth 

 cats still occur. Euceratherium is absent but the musk-ox, Symbos, 

 is recorded. Mylohyus is represented by several species in Conard 

 fissure. This genus does not occur at Hawver Cave. The bison and 

 mastodon are both absent from the former deposit. 



The above comparisons indicate that the Hawver Cave fauna rep- 

 resents distinctly an older phase of the Pleistocene than is shown by 

 the fauna from northern Arkansas. It resembles much more closely 

 the fauna from the Port Kennedy fissure and is more nearly related 

 in age to the latter than it is to the Conard fauna. 



s Brown, B., The Conard fissure, a Pleistocene bone deposit in northern Arkan- 

 sas: with descriptions of two new genera and twenty new species of mammals. 

 Mem. Amer. Mus. Nat. Hist., vol. 9, pp. 155-208, pis. 14-25, 1908. 



